In numerous strand treating operations, it is common to treat a plurality of parallel strands through a continuously moving operation. Typical of such operations is in the drying of coated strands. Examples of the drying of parallel coated strands, such as glass strands, can be found in U.S. Pat. Nos. 3,619,252 and 3,914,477.
Clearly, it is desired that these operations run continuously. However, due to any of numerous reasons, strand breakouts do occur.
In the past, when a strand breakout has occurred, it was necessary to stop the movement of the strandson either side of the broken strand and to tie the broken strand to each of the adjacent strands. The adjacent strands were then restarted, which pulled the broken strand back through the operation and rethreaded it. Finally, the adjacent strands were again stopped to untie the now threaded strand from them and restart the three strands.
During the stopping and starting of the adjacent strands, and due to the continuous nature of the drying operation, the strands stopped within the operation were overcured and thus wasted. Thus, during the entire rethreading operation, production was lost from all three affected strands. Added to this cost is the cost of splicing the partial packages of strand formed when breakouts, whether accidental, as in the strand to be repaired, or intentional, as in the rethreading strands, occur, to form acceptable size packages.
To make matters worse, in the formation of glass fiber tire cord and other elastomeric reinforcements, often three strands are twisted into a single cord after passing through the drying operation. If the broken strand is either of the two outer strands of the group of three parallel strands passing through the oven to form a single cord, as will be the case in two out of every three occurrences on the average, employing the two adjacent strands to tie the broken strand and rethread it requires not only to stop the three strands of the cord containing the broken strand but also the three strands of the adjacent cord for which one of the strands must be employed as a rethreading strand. Thus, in two out of every three strand breakouts, on the average, to repair the single broken strand the production from six strands is affected.
This stopping, tieing, restarting, stopping and final restarting operation is also time consuming. Thus, it is often found that up to 20 minutes of lost production from up to six adjacent strands may be affected from the breakout of a single strand.
It is, therefore, desirable to produce an apparatus for rethreading a broken strand in a continuous, generally parallel strand treating operation which reduces the number of strands affected by the breakout and which limits the affected strands to strands of a single cord. It is also desirable to produce an apparatus which is simple in operation and which will reduce the amount of time necessary to complete the rethreading operation.